Biology

Grimer is a slimy, amorphous blob-like Pokémon, made of living purple sludge. Its body is a pungent cesspool of bacteria, which are so potent that it renders soil barren and incapable of supporting plant life ever again. It has two large eyes with beady little pupils, and a gaping mouth with a grey tongue. While it lacks any visible legs, it does have two arms with three digits on each hand. It is constantly oozing; endlessly leaking a germ-infected fluid from all parts of its body. Pieces of it often breaks off during travel, and from these pieces new Grimer will begin to grow. When combined with another Grimer, it produces new poisonous compounds.

Due to its lack of a solid form, it is capable of squeezing into any space or crevices with relative ease. It uses this to penetrate sewage pipes so that it may feed off of the filthy waste water inside. It happily consumes and thrives off nearly any form of waste or refuse. It can be found in polluted lakes and streams, as well as within cities and factories where trash and industrial waste can be found.

In the manga

In the Pokémon Adventures manga

Koga wears a Grimer on his shoulder in the form of a ninja outfit in Pokémon Adventures. He used it extensively to smother Blue, preventing him from breathing and restrict his movement so that he would be unable to call on his Pokémon. He again used it in the battle with the evil Elite Four Agatha, to little effect.

Trivia

In Sparks Fly for Magnemite, Grimer's anime debut, Grimer had a very strong odor that made most people around the Grimer to cover their noses from the smell. However, in recent episodes, Grimer's smell has seemingly ceased to exist. This is most obvious in Camping It Up! where Dawn is given a Grimer to train, and it immediately hugs her, but no one complains about any smell.

In the recent 3D games, Grimer is black instead of purple.

Grimer shares similar traits to Koffing and Trubbish. All three Pokémon are pure Poison-types with a single evolution, roughly the same base stat totals and evolution levels, and appear to be based on a different kind of pollution; Grimer being water pollution.

Origin

It appears to be a pile of living sludge. Grimer may also be based on the imagined fear that heavy pollution, caused by the leakage and/or improper disposal of toxic/radioactive waste, may result in the creation of new and undesirable life.

Name origin

Grimer is derived from grime (dirt or filth).

Betbeter may be derived from べとべと betobeto and べたべた betabeta, both meaning sticky.